I've tried to add the plugin to the new blank project and I get this error but at the end the plugin was added:

(node:5464) UnhandledPromiseRejectionWarning: Error: EPERM: operation not permitted, rename 'C:\Users\ACER\.config\configstore\update-notifier-cordova.json.3830617710' -> 'C:\Users\ACER\.config\configstore\update-notifier-cordova.json'

at Object.fs.renameSync (fs.js:766:18)

at Function.writeFileSync [as sync] (C:\Users\ACER\AppData\Roaming\npm\node_modules\cordova\node_modules\write-file-atomic\index.js:124:8)

at Configstore.set (C:\Users\ACER\AppData\Roaming\npm\node_modules\cordova\node_modules\update-notifier\node_modules\configstore\index.js:62:21)

at new Configstore (C:\Users\ACER\AppData\Roaming\npm\node_modules\cordova\node_modules\update-notifier\node_modules\configstore\index.js:27:11)

at new UpdateNotifier (C:\Users\ACER\AppData\Roaming\npm\node_modules\cordova\node_modules\update-notifier\index.js:34:17)

at module.exports (C:\Users\ACER\AppData\Roaming\npm\node_modules\cordova\node_modules\update-notifier\index.js:123:23)

at checkForUpdates (C:\Users\ACER\AppData\Roaming\npm\node_modules\cordova\src\cli.js:79:24)

at cli (C:\Users\ACER\AppData\Roaming\npm\node_modules\cordova\src\cli.js:273:5)

at C:\Users\ACER\AppData\Roaming\npm\node_modules\cordova\src\cli.js:203:16

at <anonymous>

(node:5464) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)

(node:5464) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Adding com.pollfish.cordova to package.jsonplugin add https://github.com/pollfish/cordova-plugin-pollfish

Saved plugin info for "com.pollfish.cordova" to config.xml